Pd(II) catalysis in oxidation of maltose and lactose by acidic solution of N-bromosuccinimide

The present paper deals with the kinetics and mechanism of Pd(II) catalyzed oxidation of maltose and lactose by acidic solution of N-bromosuccinimide in the presence of Hg(OAc)(2) as scavenger. The reactions follow first order in each oxidant, i.e. NBS and catalyst, i.e. Pd(II). First order dependence of reaction on substrates, i.e. maltose and lactose at low concentration range, tends to zero order in the higher concentration range. A negative effect of Cl- and H+ is observed while Hg(OAc)(2) and succinimide show negligible effect on the reaction rate. Various activation parameters have been calculated and recorded. Gluconic and galactonic acid are identified as the main oxidation products in the case of lactose whereas gluconic acid in the case of maltose. A suitable mechanism in conformity with the kinetic results has been proposed.